Masayuki Hashimoto

Fatal air embolism as a complication of CT-guided needle biopsy of the lung.

A CT-guided needle lung biopsy carries a risk of potential air embolization. We present a rare case of air embolization after this procedure. Postmortem CT revealed air in the cerebral arteries and the left ventricle. This complication is extremely rare; however, it becomes fatal when it happens. Several points to prevent this fatal complication are discussed.

Transcatheter Arterial Embolization of Acute Arterial Bleeding in the Upper and Lower Gastrointestinal Tract with N-Butyl-2-Cyanoacrylate

PURPOSE To assess the clinical utility and safety of transcatheter arterial embolization with N-butyl-2-cyanoacrylate (NBCA) for urgent control of acute arterial bleeding in the upper and lower gastrointestinal tract. MATERIALS AND METHODS Therapeutic NBCA embolization was performed in 37 patients (39 cases; mean age, 67.8 years) with acute upper (n = 16) or lower (n = 23) gastrointestinal tract bleeding after endoscopic management had failed. Transcatheter arterial embolization was performed using 1:1 to 1:5 mixtures of NBCA and iodized oil. The most common etiologies of bleeding were colonic diverticulosis (n = 13), malignancy (n = 11), and benign ulcer (n = 7). Coagulopathy was present in 11 patients, and 23 patients were hemodynamically unstable before NBCA embolization. Histologic examination for bowel ischemia was also performed in five patients who underwent excision of the lesion after NBCA embolization. RESULTS The technical success rate was 100%. Recurrent bleeding occurred in two patients. Complete hemostasis was achieved in all 11 patients with coagulopathy. Ulcers induced by transcatheter arterial embolization were noted in 6 of 20 patients who underwent endoscopic examination; the ulcers were successfully treated with conservative measures. Histologic examination revealed that despite inflammatory reactions in and around the vessels, no intestinal necrosis secondary to NBCA embolization was found. Hepatic abscess occurred in two cases, and ischemia of the lower limb occurred in one case; these complications were managed by percutaneous drainage and bypass surgery. CONCLUSIONS Transcatheter arterial embolization with NBCA is a good treatment option with a high rate of complete hemostasis and a low recurrent bleeding rate, even in patients with coagulopathy.

CT-guided transthoracic needle biopsy using a puncture site-down positioning technique.

OBJECTIVE We have developed a new CT-guided technique using puncture site-down positioning during the biopsy. The goal of our study was to determine the efficacy and safety of this technique for biopsy of lung lesions compared with the standard technique. MATERIALS AND METHODS Medical records of 236 patients who underwent CT-guided transthoracic needle biopsy were retrospectively evaluated. This study included 89 cases that were biopsied using the standard technique (group A) and 147 cases that were biopsied using the puncture site-down positioning technique (group B). A 20-gauge automated cutting needle without coaxial technique was used in all patients. Medical records were reviewed for lesion size and location, biopsy results, and complications. RESULTS When using the standard technique, the sensitivity for malignant lesions was 96.1%; the sensitivity for benign lesions, 92.1%; and diagnostic accuracy, 94.4%. Thirty-seven patients (41.6%) had pneumothorax, with 16 (18.0%) requiring chest tube placement. When using the puncture site-down positioning technique, the sensitivity for malignant lesions was 95.4%; the sensitivity for benign lesions, 93.3%; and diagnostic accuracy, 94.6%. Nineteen patients (12.9%) had pneumothorax, with four (2.7%) requiring chest tube placement. Other complications were minimal. CONCLUSION CT-guided transthoracic needle biopsy using the puncture site-down positioning technique is an effective and safe procedure with a high diagnostic accuracy and low complication rate. This new technique is especially useful in reducing the rate of pneumothorax.

Heat Distribution in the Spinal Canal during Radiofrequency Ablation for Vertebral Lesions : Study in Swine

PURPOSE To prospectively evaluate the safety of radiofrequency (RF) ablation for vertebral lesions by monitoring the temperature in swine vertebral models with and without a cortical bone defect. MATERIALS AND METHODS The institutional animal care and use committee approved the animal studies. In vivo and ex vivo studies were performed. In the in vivo study, 20 lumbar vertebrae from six swine were locally heated by using 1- or 2-cm active-tip internally cooled electrodes. In the ex vivo study, 12 fresh pig cadaver lumbar vertebrae were extracted from four swine, and spinal tumor models with or without cortical bone defect were created by stuffing a cavity with muscle tissue and locally heated by using a 1-cm active-tip internally cooled electrode. The temperature was monitored in the spinal canal and around the vertebral body during ablation. Mann-Whitney U test was used to indicate a significant difference between groups by using 1- and 2-cm active tip in the in vivo study and between groups with and without cortical defect in the ex vivo study. RESULTS In the in vivo study in which 1- and 2-cm active-tip needles were used, the temperature in the spinal canal rose to 38.2 degrees C +/- 2.7 (standard deviation) and 45.5 degrees C +/- 6.2, respectively. The latter was significantly higher than the former (P < .001). In the ex vivo study in which tumor models with or without a cortical bone defect were used, the temperature in the spinal canal rose to 48.4 degrees C +/- 6.2 and 31.3 degrees C +/- 3.4, respectively. The former was significantly higher than the latter (P < .001). CONCLUSION For in vivo cases with a 2-cm active tip and ex vivo cases with a vertebral posterior bone defect, the temperature rose to over 45 degrees C, potentially injuring the spinal cord and peripheral nerves.

Early Steps of Dauricine Biosynthesis in Cultured Roots of Menispermum dauricum

Cultured roots of Menispermum dauricum, a rich source of the bisbenzylisoquinoline alkaloid dauricine (1), were fed with l-[U-(14)C] tyrosine, L-[3-(13)C] tyrosine, and [2-(13)C] tvramine independently, and the incorporation of possible early precursors into 1 was studied. The results demonstrated that 1 was composed of four molecules of tyrosine, and that tyramine was specifically incorporated into the isoquinoline portions of 1. The unusual chlorine-containing alkaloid acutumine (3), into which (14)C-labeled tyrosine was also incorporated, was identified as one of the main constituents in the alkaloid fraction from the roots.

Development of a Re‐Positionable Aortic Stent‐Valve: A Preliminary Study in Swine

BACKGROUND Placement of aortic stent-valves in the proper position is difficult due to the high velocity and oscillation of blood flow and anatomical characteristics. To address this problem, a re-positionable stent-valve was designed and examined in a preliminary animal experiment. METHODS Protocols for this animal study were approved by the institutional Animal Care and Use Committee. An umbrella-shaped polyurethane valve was attached at the tip of newly devised re-positionable metallic stent. The prosthesis (re-positionable stent-valve) was implanted in 5 female pigs via the right carotid artery using a 10-F introducer (Group A). As a control, the stent-without-valve was implanted in 4 female pigs (Group B). Efficacy of the valve was assessed by aortography and aortic pressure measurement. Animals were sacrificed 1 hour after stent-valve implantation for macroscopic examination. RESULTS The stent-valve was successfully implanted in all pigs. In Group A, aortography showed good function of the polyurethane valve. No significant change in diastolic pressure was noted during valve testing. In Group B, aortography and aortic pressure measurement showed massive aortic regurgitation following dysfunction of the native aortic leaflets. Post-mortem examination showed small amounts of thrombus inside the polyurethane umbrella in Group A. CONCLUSION Placement of the re-positionable stent-valve seems feasible and effective. However, the problem of thrombus formation inside the umbrella valve should be solved in future studies.

Decrease in performance status after lobectomy mean poor prognosis in elderly lung cancer patients

BACKGROUND Surgery remains the best treatment for obtaining cure in patients with resectable lung cancer, regardless of age. In elderly patients, however, the presumed fear of decreased performance status (PS) after lobectomy has resulted in the delivery of sub-optimal cancer surgery. Surgical decision making for such patients would become easier if post-lobectomy survival benefits and changes in PS were well defined. METHODS We reviewed patients aged 75 years or older who received lobectomy for non-small cell lung cancer (NSCLC) at our hospital between January 2004 and December 2014. Eastern Cooperative Oncology Group PS was preoperatively and postoperatively assessed in 137 patients. Patients were classified into 2 groups based on the change in PS: in Group 1, postoperative and preoperative PS were the same; in group 2, postoperative PS was less than preoperative PS. We compared the characteristics of patients in groups 1 and 2. RESULTS Overall 5-year survival was 47.4% in group 1 and 0% in group 2 (P<0.001). History of cardiac ischemia (P=0.001) and squamous cell carcinoma (P=0.015) were identified as significant predictors of reduced postoperative PS. CONCLUSIONS Our results show that maintenance of PS after lobectomy is expected to be associated with a good prognosis. However, reduction of PS after lobectomy indicates an extremely poor prognosis in elderly patients with lung cancer. History of cardiac ischemia and squamous cell carcinoma are possible risk factors for decreasing PS. Thus, careful patient evaluation and selection are needed when deciding whether to use lobectomy in clinical practice.

Influence of ethanol-induced pulmonary embolism on hemodynamics in pigs

AIMS AND OBJECTIVES Ethanol is widely used for the embolization treatment of vascular malformations, but it can also cause serious complications such us pulmonary hypertension, cardiopulmonary collapse and death. The complications are considered secondary to pulmonary vasospasm and ethanol-induced sludge embolism, etc., We studied the hemodynamic effects of intravenous absolute ethanol injection and ethanol sludge injection in pigs. MATERIALS AND METHODS A total of 5 pigs underwent intravenous injection of ex vivo generated ethanol-induced sludge in which residual ethanol was removed (Group S) and 4 pigs underwent intravenous injection of absolute ethanol (Group E). Hemodynamic parameters related to the pulmonary and systemic circulation were compared between the groups. RESULTS Transient pulmonary hypertension was observed in both groups and the hemodynamic changes were similar in both groups. CONCLUSIONS Sludge can induce transient pulmonary hypertension or cardiopulmonary collapse, without ethanol and may be the mechanism by which ethanol induces its adverse hemodynamic effects.

Successful removal of a trapped biliary metallic stent delivery catheter using the percutaneous approach.

Endoscopic biliary self-expandable metallic stent insertion via the papilla of Vater is a treatment of choice for malignant biliary obstruction caused by unresectable biliary neoplasms. Stent migration is a problem after stent insertion. The clinical presentations of patients with stent migration include stent malfunction and perforation of the intestinal wall [1, 2]. It is a relatively rare complication for a stent delivery catheter to migrate and become trapped. An interesting case of successful removal of a trapped delivery catheter through the percutaneous approach is reported.

Discordant uptake of Tc-99m PMT and Tc-99m GSA by two hepatocellular carcinoma lesions

Tc-99m PMT and Tc-99m GSA can be taken up by hepatocellular carcinoma (HCC), but there has been no report concerning HCC showing accumulation of both of Tc-99m PMT and Tc-99m GSA. In this paper we describe a case of two simultaneously developed HCCs, one of which took up both tracers but the other took up neither of them.